The S511 viewing head employs a Ge (germanium) photo detector which
responds to a spectral range of 750-1900nm (nanometers). It will detect all
types of flames including natural gas and propane.
The S511 is a bonafide infrared flame detector that detects all flame and
is particularly useful for application where the combustion process might be
considered inconsistent or unstable such as those found in the process
industries. For example, the S511 works well on lime kilns because the AGC
creates a more uniform flame signal throughout the different combustion
stages. It also works well on sour gas (sulfur recovery) application
principally because of the AGC action.
The signal from the detector is a flicker signal. All flames pulsate
creating a flicker component which is what the S511 detects. The flicker
frequencies emitted from flames range 0-2000Hz. The S511 responds to only the
higher frequencies while rejecting the lower frequencies which are part of the
general furnace or background flames.
The Ge element is a photodiode that is operated in the photovoltaic mode.
(The diode generates current when exposed to light or radiation). The
sensitivity range of this element is quite large so some means to prevent
saturation in the first stage of amplification is required. (The PbS element
has a rather limited dynamic range exhibiting not more than 15:1 ratio from
dark to a bright signal). In order to prevent saturation an AGC (automatic
gain control) circuit is used so that the DC component or "brightness" signal
doesn't saturate causing a loss of the AC component or flicker signal.
The S511 employs electronics self-checking which is implemented by using an
electronic switch that disconnects the photo detectors every second for 200
milliseconds. The resulting chopped signal is fed to the signal processor
which monitors the signal in a fail-safe manner.
Please call or email for pricing and availability at 281-421-1321 or firstname.lastname@example.org.